A Comprehensive Evaluation Method of Energy Storage Battery Health Status Based on Combined Weights of Lifetime Characteristics and Operating Characteristics

As an important link to promote renewable energy consumption and ensure the normal operation of power system, the comprehensive evaluation of the health status of battery energy storage system is of great significance to improve the safety and stability of energy storage power plant operation. In this context, this paper takes battery energy storage system as the research object, focuses on the health status of energy storage battery, conducts innovative research on the establishment of its evaluation index system, and aims to propose a method of evaluating the health status of energy storage battery based on the combination of subjective and objective assignment method. Firstly, the evaluation index system including life time characteristics and operational safety is constructed to reflect the performance of the actual operation of the energy storage power plant comprehensively. Then, the subjective and objective weights are calculated based on Analytic Hierarchy Process (AHP) and inverse entropy weighting method and the optimal combination weights are obtained. Finally, a comprehensive evaluation model of energy storage battery health state is established based on the combination weights. The evaluation model is applied to three energy storage battery packs of a battery storage system, and the evaluation results are consistent with the actual operation, achieving an objective and reasonable evaluation of the health status of the energy storage battery, which is important for improving the safe and efficient operation of the power grid.